In a prior art, a solid object existing ahead of the driver's own vehicle is detected, and when it is predicted that the driver's own vehicle will collide with the detected solid object, brake is actuated electrically to avoid a collision with the solid object by its braking force. However, in collision avoidance utilizing only braking force, the braking force varies depending on the condition of the road surface and the condition of tires, and collision avoidance sometimes necessitates sudden braking. In view of this, in a prior art, a collision avoidance operation by turning is performed when it is not possible to avoid a collision reliably by braking force (see, for example, patent document 1).